That's alright for a few hours, but for days . . . yuck!!!!
Don't despair, folks. Every one of those high-rise hotels and other buildings in New Orleans is built upon steel pilings that are embedded in bedrock. By law they have to be, because New Orleans' soft soil will not support multistory construction built upon surface foundations. These structures will survive the winds and floods. The people in these buildings can survive as well as long as they stay above the fourth floor and lie low to avoid flying glass and other missiles during the strike itself.
As far as the aftermath goes, a big-city hotel is actually a pretty good survival shelter: solid concrete and steel construction, wide stairways, and plenty of sleeping space. Water is readily available in a hotel: every toilet in the building will have 1-3 gallons of clean, drinkable water in its tank, and then there are the big hot water heater tanks and indoor swimming pools that can be drained. The toilets won't flush anymore of course, but human waste can be disposed of by simply throwing it off a balcony. As far as food goes, it's a fact that healthy people can survive two to three weeks without any food at all, but then again there are are vending machines on every floor and you'd be surprised how long a person can live on a diet of Fritos and Diet Dr Pepper provided they have access to potable water. The pantries and minibars will contain food as well. Liquor from the bar can be used as a disinfectant, tranquilizer, and anesthetic if necessary. And there are clothes, blankets, soap, and other amenities to spare.
In short, those people trapped in high-rise buildings stand a good chance of living through this thing, so don't give up hope yet. In the end, we are Americans, and Americans are notoriously difficult to kill. Chins up, gang.